In conventional aircraft multiple disc brakes having an annular pressure plate, it has been the practice to provide a plurality of circumferentially arranged spaced apart fluid pressure actuated pistons connected to actuate the brake upon demand and a plurality of circumferentially arranged spaced apart brake adjust/reset devices operatively connected to the pressure plate between the pistons for adjusting the axial position of the pressure plate to compensate for wear of the brake discs and permit retraction of the pressure plate to maintain a predetermined running clearance between discs upon release of the brake. Reference is made to U.S. Pat. No. 3,376,959 to O. L. Holcomb, Jr. et al for an example of a conventional brake having the above-mentioned characteristics.
It has been found that such conventional brake piston and adjuster/reset arrangements are not entirely satisfactory due to distortion of the annular pressure plate resulting from uneven force distribution thereon as a consequence of the spaced apart brake adjust/reset devices and the position of the same relative to the brake actuating pistons.
At least one known attempt has been made to combine the piston and adjuster/reset apparatus to thereby place the same as well as the forces derived therefrom in coaxial relationship. Reference is made to U.S. Pat. No. 3,729,072 to D. F. Borkowski for a detailed description of the above-mentioned combined piston and adjuster/reset device which has distinct advantages over the prior art devices but which is not without certain undesirable features. It has been found that wear or other deterioration such as metal fatigue or the like of the component members of the brake actuating piston and adjuster/reset device is accelerated by wear and/or brake vibration which, in the case of exposure to the pressurized brake fluid, results in undesirable particle contamination of the working pressurized fluid. Another undesirable characteristic feature of many related prior art structures is a requirement for partial or complete disassembly of the disc brake structure to gain access to the brake actuating piston and adjuster/reset mechanism for routine maintenance or repair of the same.